Betsy Cromer Byars (born August 7, 1928) is an American author of children's books. Her novel Summer of the Swans won the 1971 Newbery Medal. She has also received a National Book Award, for The Night Swimmers (1980), and an Edgar Award, for Wanted...Mud Blossom (1991). In 1987 she received the Regina Medal, for lifetime achievement, from the Catholic Library Association.

Byars was born Betsy Cromer August 7, 1928, in Charlotte, North Carolina. She attended Furman University in Greenville, South Carolina, from 1946 to 1948, and graduated in 1950 from Queens College in Charlotte, with a bachelor's degree in English.

Cromer married Ed Byars June 24, 1950, and they had three daughters and a son between 1951 and 1958. In 1956, she began writing for magazines. Her first book, Clementine, was published in 1962.

Betsy and Ed Byars are both licensed aircraft pilots and live on an airstrip in Seneca, South Carolina, the bottom floor of their house being a hangar.

Daughters Betsy Duffey and Laurie Byars are also children's authors, and the three of them are currently (as of February 2009) working on their fourth book together.